A&P

anything that has mass and occupies space

Solid - definite shape and volume (i.e. bone)

Liquid - definite volume, changeable shape (blood)

Gas - changeable shape and volume (air)

Energy is the capacity to do work or put matter into motion.

Has no mass

Kinetic - energy in action

Potential - stored/inactive energy

• Chemical energy - stored in bonds of chemical substances
• Electrical energy - results from movement of charged particles
• Mechanical energy - directly involved in moving matter
• Radiant or electromagnetic energy - exhibits wavelike properties (visible light, ultraviolet light, x-rays)

energy may be converted from one form to another (i.e. from kinetic to potential energy when drawing an arrow)

conversion is inefficient because some energy is "lost" as heat

cannot be broken down by ordinary chemical means

• each element has unique properties:
• physical properties = detectable with our senses, or are measurable
• chemical properties = how atoms interact (bond) with one another

unique building blocks for each element

one or two letter chemical shorthand for each element

• Oxygen (O)
• Carbon (C)
• Hydrogen (H)
• Nitrogen (N)

These make up about 96% of body mass

• These are about 3.9% of body mass:
• Calcium (Ca)
• Phosphorus (P)
• Potassium (K)
• Sulfur (S)
• Sodium (Na)
• Chlorine (Cl)
• Magnesium (Mg)
• Iodine (I)
• Iron (Fe)

• are typically part of enzymes
• <0.01% of body mass:
• Chromium (Cr)
• Manganese (Mn)
• Zinc (Zn)

• Determined by numbers of subatomic particles
• nucleus consists of neutrons and protons

• Neutrons
• No charge
• Mass = 1 atomic mass unit (amu)
• Protons
• positive charge
• mass = 1 amu
• Electrons
• orbit nucleus
• equal in # to protons in atom
• negative charge
• 1/2000 the mass of a proton (0 amu)

• Orbital model = current model used by chemists. Depicts probable regions of greatest electron density (an electron cloud).  Useful for predicting chemical behavior of atoms.
• Planetary model = oversimplified, outdated model. Incorrectly depicts fixed circular electron paths.  Useful for illustrations.

atoms of different elements contain different #s of subatomic particles

• Atomic number = # protons in nucleus (periodic table)
• Mass number = mass of the protons and neutrons
• --- mass numbers of atoms of an element are not all identical
• --- isotopes are structural variations of elements that differ in the number of neutrons they contain
• Atomic weight = average of mass numbers of all isotopes

• spontaneous decay (radioactivity)
• similar chemistry to stable isotopes
• can be detected with scanners
• valuable tools for biological research and medicine

Cause damage to living tissue; useful against localized cancers; radon from uranium decay causes lung cancer

• Most atoms combine chemically with other atoms to form molecules and compounds
• Molecule = two or more atoms bonded together (e.g. H2 or C6-H12-O6)
• Compound = two or more different kinds of atoms bonded together (e.g. C6-H12-O6)

Most matter exists as mixtures; 2 or more components physically intermixed

• 3 types of mixtures
• solutions (salt water)
• colloids (milk - fat globules dispersed in a watery solution)
• suspensions (mud - sand suspended in water)

• homogeneous mixtures
• usually transparent, e.g. atmosphere, air, or seawater

• Solvent = present in greatest amount, usually a liquid
• Solute(s) = present in smaller amounts

expressed as:

• Percent or parts per 100 parts
• milligrams per deciliter (mg/dl)
• molarity or moles per liter (M)
• --- 1 mole = the atomic weight of an element or molecular weight (sum of atomic weights) of a compound in grams
• --- 1 mole of any substance contains 6.02 x 10^23 molecules (Avogadro's number)

colloids (emulsions)

heterogeneous translucent mixtures (cytosol)

large solute particles that do not settle out

undergo sol-gel transformations

heterogeneous mixtures (blood)

large, visible solutes tend to settle out, and may scatter light

• Mixtures
• no chemical bonding between components
• can be separated physically, such as by straining or filtering
• heterogeneous or homogeneous

• Compounds
• can be separated only by breaking bonds
• all are homogeneous